LFI Reagent Buffer Composition for Clearer COVID-19 Antigen Bands
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing reagent buffers for lateral flow immunoassays (LFIs) face challenges in effectively extracting and neutralizing SARS-CoV-2 antigens while maintaining optimal fluid flow rates and reducing non-specific binding, which affects the clarity and intensity of diagnostic signals in COVID-19 antigen testing.
Innovation Solution
A reagent buffer comprising a zwitterionic sulfonic solution, non-ionic surfactant, and buffer solution with a pH range of 7.0 to 8.0 and specific absorbance peaks, optimized to improve flow characteristics, reduce background signals, and enhance band intensity and thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional reagent buffers are used for SARS-CoV-2 antigen extraction, then the buffer can perform basic extraction function, but the fluid flow rate through the LFI strip is suboptimal and non-specific background signals increase
Solution Approach 1:
The patent modifies the chemical composition parameters of the reagent buffer by incorporating zwitterionic sulfonic acid compounds (such as HEPES, CAPS, or CHES) at specific concentrations (10-500 mM), combined with non-ionic surfactants (0.1-5% v/v) and salts. This parameter optimization resolves the contradiction by simultaneously improving fluid flow characteristics through the nitrocellulose membrane and reducing non-specific hydrophobic interactions that cause background signals.
Solution Approach 2:
The patent creates a composite reagent buffer system that integrates multiple functional components: zwitterionic sulfonic acid compounds (for pH buffering and reducing non-specific binding), non-ionic surfactants (for preventing hydrophobic interactions), and salts (for ionic strength optimization). This composite approach enables the buffer to simultaneously achieve optimal flow rates and minimize background signals by addressing multiple factors concurrently.
2Object-generated harmful factors
If the reagent buffer contains surfactants and blocking proteins to prevent non-specific binding, then background signals are reduced, but the complexity of buffer composition increases
Solution Approach 1:
The patent optimizes the concentration parameters of each buffer component to achieve effective non-specific binding prevention at moderate levels. By specifying precise concentration ranges (e.g., zwitterionic compounds at 10-500 mM, surfactants at 0.1-5%), the patent simplifies buffer preparation while maintaining effectiveness, resolving the contradiction between reducing background signals and maintaining composition complexity.
3Productivity
If the reagent buffer is optimized for rapid antigen extraction, then the diagnostic speed is improved, but the sensitivity and accuracy of antigen detection may be compromised
Solution Approach 1:
The patent optimizes multiple buffer parameters simultaneously - pH (using zwitterionic buffers with pKa 6.0-8.0 for physiological compatibility), ionic strength (via salt concentration), and surfactant levels - to achieve a balance where rapid antigen extraction occurs without compromising antibody-antigen binding specificity. This multi-parameter optimization enables both rapid diagnostics and high sensitivity detection.
Solution Approach 2:
The zwitterionic sulfonic acid compounds act as intermediary substances that facilitate rapid antigen extraction while maintaining a chemical environment conducive to specific immunological binding. These compounds mediate between the extraction efficiency requirement and the binding specificity requirement, enabling both rapid processing and accurate detection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The optimized reagent buffer achieves rapid and accurate SARS-CoV-2 antigen detection with improved fluid flow, reduced non-specific binding, and enhanced signal clarity and intensity, ensuring reliable diagnostic results.
Implementation Method 1
the reagent buffer must prevent non-specific hydrophobic interactions on the reaction matrix to both improve the diagnostic signal and improve the clarity of the diagnostic signal
Implementation Method 2
the reagent buffer must properly re-hydrate the dry LFI strip to improve fluid flow rate performance
Data Source
AI summary
An embodiment relates to a reagent buffer comprising a zwitterionic sulfonic solution, a non-ionic surfactant solution, and a buffer solution, wherein the reagent buffer has a pH range of about 7.0 to about 8.0 and a circular dichroism with an absorbance peak more than 0 at 190 nm and 225 nm. In an embodiment, the reagent buffer is configured to be a reagent buffer for a lateral flow immunoassay for detection of COVID-19.